Merge pull request 99designs#239 from vektah/directive-args

Directive args

codegen/build.go

@@ -141,6 +141,10 @@ func (cfg *Config) bind() (*Build, error) {
 	if err != nil {
 		return nil, err
 	}
+	directives, err := cfg.buildDirectives(namedTypes)
+	if err != nil {
+		return nil, err
+	}
 
 	b := &Build{
 		PackageName:    cfg.Exec.Package,
@@ -150,7 +154,7 @@ func (cfg *Config) bind() (*Build, error) {
 		Imports:        imports.finalize(),
 		SchemaRaw:      cfg.SchemaStr,
 		SchemaFilename: cfg.SchemaFilename,
-		Directives:     cfg.buildDirectives(),
+		Directives:     directives,
 	}
 
 	if cfg.schema.Query != nil {

codegen/directive.go

@@ -1,5 +1,33 @@
 package codegen
 
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
 type Directive struct {
 	Name string
+	Args []FieldArgument
+}
+
+func (d *Directive) CallArgs() string {
+	args := []string{"ctx", "n"}
+
+	for _, arg := range d.Args {
+		args = append(args, "args["+strconv.Quote(arg.GQLName)+"].("+arg.Signature()+")")
+	}
+
+	return strings.Join(args, ", ")
+}
+
+func (d *Directive) Declaration() string {
+	res := ucFirst(d.Name) + " func(ctx context.Context, next graphql.Resolver"
+
+	for _, arg := range d.Args {
+		res += fmt.Sprintf(", %s %s", arg.GoVarName, arg.Signature())
+	}
+
+	res += ") (res interface{}, err error)"
+	return res
 }

codegen/directive_build.go

@@ -1,13 +1,42 @@
 package codegen
 
-func (cfg *Config) buildDirectives() (directives []*Directive) {
-	for name := range cfg.schema.Directives {
+import "github.com/pkg/errors"
+
+func (cfg *Config) buildDirectives(types NamedTypes) ([]*Directive, error) {
+	var directives []*Directive
+
+	for name, dir := range cfg.schema.Directives {
 		if name == "skip" || name == "include" || name == "deprecated" {
 			continue
 		}
+
+		var args []FieldArgument
+		for _, arg := range dir.Arguments {
+			newArg := FieldArgument{
+				GQLName:   arg.Name,
+				Type:      types.getType(arg.Type),
+				GoVarName: sanitizeGoName(arg.Name),
+			}
+
+			if !newArg.Type.IsInput && !newArg.Type.IsScalar {
+				return nil, errors.Errorf("%s cannot be used as argument of directive %s(%s) only input and scalar types are allowed", arg.Type, dir.Name, arg.Name)
+			}
+
+			if arg.DefaultValue != nil {
+				var err error
+				newArg.Default, err = arg.DefaultValue.Value(nil)
+				if err != nil {
+					return nil, errors.Errorf("default value for directive argument %s(%s) is not valid: %s", dir.Name, arg.Name, err.Error())
+				}
+				newArg.StripPtr()
+			}
+			args = append(args, newArg)
+		}
+
 		directives = append(directives, &Directive{
 			Name: name,
+			Args: args,
 		})
 	}
-	return directives
+	return directives, nil
 }

codegen/object.go

@@ -219,6 +219,10 @@ func (f *Field) doWriteJson(val string, remainingMods []string, isPtr bool, dept
 	}
 }
 
+func (f *FieldArgument) Stream() bool {
+	return f.Object != nil && f.Object.Stream
+}
+
 func (os Objects) ByName(name string) *Object {
 	for i, o := range os {
 		if strings.EqualFold(o.GQLType, name) {

codegen/templates/args.gotpl

@@ -1,30 +1,17 @@
 	{{- if . }}args := map[string]interface{}{} {{end}}
 	{{- range $i, $arg := . }}
 		var arg{{$i}} {{$arg.Signature }}
-		if tmp, ok := field.Args[{{$arg.GQLName|quote}}]; ok {
+		if tmp, ok := rawArgs[{{$arg.GQLName|quote}}]; ok {
 			var err error
 			{{$arg.Unmarshal (print "arg" $i) "tmp" }}
 			if err != nil {
 				ec.Error(ctx, err)
-				{{- if $arg.Object.Stream }}
-					return nil
-				{{- else }}
-					return graphql.Null
-				{{- end }}
-			}
-		} {{ if $arg.Default }} else {
-			var tmp interface{} = {{ $arg.Default | dump }}
-			var err error
-			{{$arg.Unmarshal (print "arg" $i) "tmp" }}
-			if err != nil {
-				ec.Error(ctx, err)
-				{{- if $arg.Object.Stream }}
+				{{- if $arg.Stream }}
 					return nil
 				{{- else }}
 					return graphql.Null
 				{{- end }}
 			}
 		}
-		{{end }}
 		args[{{$arg.GQLName|quote}}] = arg{{$i}}
 	{{- end -}}

codegen/templates/field.gotpl

@@ -3,7 +3,10 @@
 
 {{- if $object.Stream }}
 	func (ec *executionContext) _{{$object.GQLType}}_{{$field.GQLName}}(ctx context.Context, field graphql.CollectedField) func() graphql.Marshaler {
-		{{- template "args.gotpl" $field.Args }}
+		{{- if $field.Args }}
+			rawArgs := field.ArgumentMap(ec.Variables)
+			{{ template "args.gotpl" $field.Args }}
+		{{- end }}
 		ctx = graphql.WithResolverContext(ctx, &graphql.ResolverContext{Field: field})
 		results, err := ec.resolvers.{{ $field.ShortInvocation }}
 		if err != nil {
@@ -22,7 +25,10 @@
 	}
 {{ else }}
 	func (ec *executionContext) _{{$object.GQLType}}_{{$field.GQLName}}(ctx context.Context, field graphql.CollectedField, {{if not $object.Root}}obj *{{$object.FullName}}{{end}}) graphql.Marshaler {
-		{{- template "args.gotpl" $field.Args }}
+		{{- if $field.Args }}
+			rawArgs := field.ArgumentMap(ec.Variables)
+			{{ template "args.gotpl" $field.Args }}
+		{{- end }}
 
 		{{- if $field.IsConcurrent }}
 			ctx = graphql.WithResolverContext(ctx, &graphql.ResolverContext{

codegen/templates/generated.gotpl

@@ -31,7 +31,7 @@ type ResolverRoot interface {
 
 type DirectiveRoot struct {
 {{ range $directive := .Directives }}
-	{{$directive.Name|ucFirst}} graphql.FieldMiddleware
+	{{ $directive.Declaration }}
 {{ end }}
 }
 
@@ -155,9 +155,13 @@ func (ec *executionContext) FieldMiddleware(ctx context.Context, next graphql.Re
 		{{- range $directive := .Directives }}
 		case "{{$directive.Name}}":
 			if ec.directives.{{$directive.Name|ucFirst}} != nil {
+				{{- if $directive.Args }}
+					rawArgs := d.ArgumentMap(ec.Variables)
+					{{ template "args.gotpl" $directive.Args }}
+				{{- end }}
 				n := next
 				next = func(ctx context.Context) (interface{}, error) {
-					return ec.directives.{{$directive.Name|ucFirst}}(ctx, n)
+					return ec.directives.{{$directive.Name|ucFirst}}({{$directive.CallArgs}})
 				}
 			}
 		{{- end }}